Subscribing to Scientific American on line, I received today this interesting paper:

Quote

Evolutionary Origins of Your Right and Left BrainThe division of labor by the two cerebral hemispheres—once thought to be uniquely human—predates us by half a billion years. Speech, right-handedness, facial recognition and the processing of spatial relations can be traced to brain asymmetries in early vertebratesBy Peter F. MacNeilage, Lesley J. Rogers and Giorgio Vallortigara From the July 2009 Scientific American Magazine

The paper is accessible, as most of the times Scientific American papers. It provides a summary view of the subject matter. Not for specialists of course, but could be useful as general background "scientific varnish"...